Dehydrating apparatus



Aug. 4, 1931. R. M. WASHBURN DEHYDRATING APPARATUS Filed Dec. 51, 1928 4 Sheets-Sheet 1 g- 4, 1931- R. M. WASHBURN 1,817,048

DEHYDRATING APPARATUS Filed Dec. 31, 1928 4 Sheets-Sheet 2 4, 1931- R. M. WASHBURN 1,817,048

DEHYDRATING APPARATUS Filed Dec. 31, 1928 4 Sheets-Sheet 5 1/5 70 Tker ask/141W g- 19311 R. M. WASHBURN. 1, ,0 8

DEHYDRAT ING APPARATUS Filed Dec. 51,' 1923 4 Sheets-Sheet 4 Patented Aug. 4, 1931 UNITED STATES PATENT orricr J ROBERT M. WASHBURN', or EvAnsroN, I imoIs'; hssrenon; BY MESNE ASSIGNMENTS,

'ro ALBERT r. HUNT nnrrrnnAmue APPARATUS p Application filed December 31, 1928. Serial No. 329,6 04f This invention relates to dehydrating apparatus and more particularly to the construction of such apparatus for facilitating the recovery of finely comminuted dried material from the gaseous carrying medium associated therewith.

In systems heretofore devised, for the dehydration of liquid substances and for the recovery of the dust-like product resulting from such dehydration, no provision, or at best unsatisfactoryprovision, has sometimes been made for removing the powdered product as fast as it is formed from the heated drying chamber. In some cases considerable quantities of the powdered product are allowed to accumulate in the bottom portion of the drying chamber, there to be subjected to the influence of long continued, comparatively high temperatures, which in the case of certain products, are highly detrimental to the quality thereof; In other systems, special, intricate and expensive arrangements for the removal of the final product -from the dehydrating chamber have been devised.

It is an object of this invention to provide a dehydrating apparatus and means associated therewith for continuously and automatically removing the dried product from the dehydration chamber.

It is a further important object of thisinvention to provide animproved system'of removing the dried powdered product from dehydrating apparatus and for elficiently separating the dried powdered material from the gaseous medium with which it is associated. Other and further important objects of this invention will become apparent from the following description and the accompanying drawings.

This invention (in a preferred form) is illustrated in the drawings and hereinafter more fully described. I

On the drawings: T 1

Figure 1 is a front elevational view of a dehydrating apparatus embodying the principles of my invention; 7

Figure 2 is a broken side elevational view of-the same with parts broken away to show the spraying device; A

1, preferably near the top thereof andprosource ofpower, and adapted to deliver the Figure 3 is a sectional view taken substantially on line IIIIII0 Figure 1; Figure 4 is an enlarged sectional view taken substantially on line IVIV of Figure 2;

:VIVI'0f Fig. 4; and

' Figure is an enlarged fragmentary sectional view taken substantially on line VII-+VII of Fig. 2.

I As shown on the. drawings The reference numeral 1 indicates as a Whole a dehydrating chamber, which asillus trated is of rectangular cross-section, although the particular shape, form and de-Q of the dehydrating chamber is of no par- '70 ticular importance so far as the present invention is concerned. v

Any suitable .form of spraying device 2' may be mounted within saiddrying chamber vided with a hollow conduit 3 leading through the top of said chamber 1 for the introduction of liquid material to said spraying device 2.

,A- gaseous dehydrating medium, such as heated air, is adapted to be introduced-into said-drying chamber 1 through 'a plurality of ports'4 arranged in opposite side walls of said chamber 1 near .the top thereof and communicatin by means of ducts 5 and conduits 6 with a urnace7, or other source of heat. The air is drawn into the system through an a open box 8' by means of a fan 9, driven through the pulley 10 from any suitable air through a conduit 11 to said furnace 7, and from thence through the conduit 6 and ducts 5 to the ports 4'. 1

In accordance with the principles of my invention the dehydrating chamber 1 is providedwith one or more hopper shaped bottoms 12 formed by downwardly converging bottom walls13 and 14. 1 Said bottom walls 13 and 14, which may be sloped at any suitable angle, say 45., -provide' a lower opening,

or slot extending the full width of the'dehydrating chamber 1 and tapering from one end to the other. I

A conduit 16 extends beneath each of said slots 15 and opens through said slots 15 into the interior of said drying chamber 1. Said conduit 16 is likewise tapered but in the reverse direction to the taper of said slots 15. The conduit 16 begins at the wider end of the slot 15 as at 17 and is of gradually increasing cross-sectional area until it reaches its full diameter at the narrow end of said slot 15 as at 18. -A continuation 19 of the conduit 16 extends from the point 18 to the top of a dust separator or collector 20, preferably of the cyclone type. The separated dried powder passes out of the separator 20 through a spout 21 and flap valve 22 onto a vibrating tray, in-

dicated as a whole by the reference numeral 23. Said tray 23 may be suitably mounted upon rollers24 and connected at one end by a rod 25 and eccentric pin 26 to a disc 27, said disc 27 being mounted upon a shaft 28 adapted to be driven through a sprocket gear 29 by a chain 30. From the vibrating tray 23, the product falls through a bottom spout 31 into a suitable receptacle placed therebeneath.

The separated gases are led from the top of the separator 20 through a conduit 32 and scrubber 33 by means of a fan or blower 34.

Said fan 34, which may be suitably driven as through a pulley 35, discharges the waste gases through a stack 36.

. In the scrubber '33, the waste gases may pass through a shower of water or other liquid, preferably the liquid to be dehydrated, to remove whatever particles of dust may be carried beyond the separator 20.

The operation of the dehydrating appara-.

tus is substantially as follows:

The liquid to be dehydrated is introduced 1 to. the spraying device 2 through the conduit 3 and is sprayed thereby into the top of the dehydrating chamber'l. Opposing currents of heated air are blown into the dehydrating chamber 1 through the ports 4 by means of the fan 9 and conduits 11 and 6. The dehydrated v material, now. in the form of dust-like particles, is deposited upon the sloping bottom walls 13 and 14, which are at such angles as to cause the powder to slide down into the slot or opening 15.

As the slot 15 is narrower at the'end 18 nearest the cyclone separator'20, and -gradually widens toward the opposite end of "the conduit 16, and as the taper of the conduit 16 is the reverse of that of the slot 15 the tendency is to equalize the volume and. ve-

locity of air passing through the slot 15 at j diflerent points throughout its length. The total area of the slot 15 is such that the total quantity of air may readily pass through it without undue force being required and the same is true also of the cross-sectional area of the conduit 16 at any given point. The

fact that the slot l5 is relatively narrow insures a rather strong downdraft of air along the sloping bottom walls 13 and 14, with the result that any powder lodging thereon is drawn with the downdraft through the slot 15 into the conduit 16. v

In passing through the dust separators 20, of which one or any number may be used, the powdered product is separated out from its gaseous carrying medium and falls Preferably, sprays of the liquid to be dehydrated are used in said scrubber 33, in order to utilize the heat values of said waste gases to preheat and partially evaporate said liquid, while at the same time enriching it by the recovery of such dust particles as escape separation in the separator 20.

Y I am aware that many changes may be made and numerous details of construction may be varied through a Wide range without 1 departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted'hereon' otherwise than necessitated by the prior art.

I claim as my invention: 1. In apparatus for drying finely commlnuted material in a heated gaseous medium, a

hopper shaped bottom having a lower tapered discharge opening, a conduit beneath said opening of gradually increasing cross section toward the smaller end of said tapered opening and means for drawing a current of gaseous medium and suspended dried particles, through said, tapered opening -into said conduit.'

2. In apparatus for collecting dried powdered material suspended in a gaseous me dium, a chamber having converging walls forming an opening therebetween, tapering in its width, a conduit running lengthwise of said opening with its exit near the narrow end thereof and means for creating a draft in said conduit to draw said powdered material and gaseous medium through said tapered opening into said conduit.

3. In apparatus for collecting dried powdered material suspended in a gaseous medium, a chamber having converging bottom walls forming an opening therebetween, ta pering in its width and running substantially the width of said chamber, a conduit running lengthwise of said opening with its exit near the narrow end thereof and means for creating a draft in said'conduit to draw said powdered material and gaseous medium duit.

4. In apparatus for collecting dried pow- 1 dered material suspended in a gaseous medium, a chamber having converging bottom walls forming an opening therebetween, ta pering in its width, a conduit running lengthwise of and beneath said opening with its exit near the narrow end thereof and means connected to said conduit for creating a draft to draw said powdered material and gaseous medium through said tapered opening into said conduit. 7

5. In a dehydrating apparatus, a dehydrating cell and a conduit leading therefrom for the removal of waste gases and dehydrated material, said conduit having a tapered slot opening into the interior of said cell withthe narrow end of said slot toward-the exit end of said conduit.

6. In a dehydrating apparatus, a dehydrating cell and a conduit leading therefrom for the removal of waste gases and dehydrated material, said conduit having a tapered slot opening into the interior of said cell with the narrow end of said slot toward the exit end of said conduit and said conduit being of reversely tapered cross section with respect to said slot. r

- 7. In a dehydrating apparatus, a dehydrating cell, a conduit leading therefrom for the removal of wastegases and dehydrated 'material, said conduit having a tapered 'slot opening into the interior of said cell with the narrow end of said slot toward the exit end of said conduit, and convergent wall members adapted to direct said gases and dehydrated material into said slot. I

8. In a dehydrating apparatus, a dehydrating cell, a conduit leading therefromfor the removal of waste gases, and dehydrated ma-* terial, said conduit having a tapered slot opening into the interior of said cell with the narrow end of said slot toward the exit end of said conduit and said conduit being of reversely tapered cross section with respect 7 to said slot, and convergent wall members adapted to direct said gases and dehydrated material into said slot.

In testimony whereof I have hereunto subscribed my name atChicago, Cook County,

Illinois.

ROBERT M. WASHBURN. 

